Nuprl Lemma : member-concat

∀[T:Type]. ∀ll:T List List. ∀x:T.  ((x ∈ concat(ll)) ⇐⇒ ∃l:T List. ((l ∈ ll) ∧ (x ∈ l)))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  concat: concat(ll),  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  prop: ℙ,  and: P ∧ Q,  so_apply: x[s],  implies: P ⇒ Q,  concat: concat(ll),  top: Top,  iff: P ⇐⇒ Q,  false: False,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  or: P ∨ Q,  cand: A c∧ B,  guard: {T}
Lemmas referenced :  list_induction,  list_wf,  all_wf,  iff_wf,  l_member_wf,  concat_wf,  exists_wf,  reduce_nil_lemma,  false_wf,  nil_member,  nil_wf,  reduce_cons_lemma,  or_wf,  equal_wf,  cons_member,  cons_wf,  member_append,  append_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  sqequalRule,  lambdaEquality,  productEquality,  independent_functionElimination,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  productElimination,  addLevel,  allFunctionality,  impliesFunctionality,  because_Cache,  existsFunctionality,  andLevelFunctionality,  existsLevelFunctionality,  rename,  universeEquality,  unionElimination,  dependent_pairFormation,  inlFormation,  inrFormation,  equalitySymmetry,  hyp_replacement,  Error :applyLambdaEquality

Latex:
\mforall{}[T:Type].  \mforall{}ll:T  List  List.  \mforall{}x:T.    ((x  \mmember{}  concat(ll))  \mLeftarrow{}{}\mRightarrow{}  \mexists{}l:T  List.  ((l  \mmember{}  ll)  \mwedge{}  (x  \mmember{}  l)))



Date html generated: 2016_10_21-AM-10_33_57
Last ObjectModification: 2016_07_12-AM-05_46_02

Theory : list_1


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